BEIJING
— Leaders of two of the most unlikely states in Asia, Japan and North Korea, shake hands Tuesday in a major effort to normalize relations, after a two-year diplomatic freeze and almost a century of hostility. Junichiro Koizumi, elected leader of the world's second largest economy, and Kim Jong Il, inheritor of the world's most closed and controlled state, will talk for several hours in Pyongyang, on the first visit ever by a Japanese leader to the North Korean capital.

If Prime Minister Koizumi secures prospects for normalized diplomatic relations with Mr. Kim  a relationship Tokyo and Pyongyang have never had  the visit could well be regarded as historic. The two states, separated by the Sea of Japan, have suffered dysfunctional relations and deep animosity dating to Japan's 35-year occupation of Korea, which ended in 1945.

Normalization would put Japan on important new footing in the region, analysts say. The beleaguered nation would improve ties with both Koreas, creating a climate of greater congeniality between North and South. Such diplomatic success could also win Koizumi plaudits at home.

The summit comes as the US is preoccupied with a possible Iraq campaign. Indeed, the diplomacy seems to many analysts a bid by the Japanese to break out of a deep-freeze over North Korea often blamed privately, in Tokyo, on US inattention due to the war on terror, or on a lack of US strategy on the North.

The Bush team has been divided over how tough to be on North Korea, with strong hawks battling lesser hawks.

"The Koizumi effort is the only way to 'end run' the current [Bush administration] logjam on Korea policy," a highly placed US government adviser says.

Koizumi will carry to Pyongyang a promise of some $10 billion in aid  a figure comparable to the compensation paid when Japan normalized with South Korea in 1965, and a sign of Japanese apology for World War II occupation.

As always with the North, the wild card is the mercurial Kim. The leader is viewed with great skepticism in Asia, based on his history of making, then breaking, deals.

But Kim, for his part, faces shortages of food, power, and funds: North Korea's economy has shrunk by half in recent years, and desperately needs foreign currency. Moreover, a sunny summit could also benefit the North by revitalizing South Korea's now-troubled "Sunshine Policy." President Kim Dae Jung, originator of the policy that supported taking baby-steps toward normalized diplomatic relations, faces a national election this December against opponents far less willing to engage generously with the North.

Kim, who recently termed the summit "epochmaking," has lately shown a willingness to distance himself from fellow "axis of evil" list leader Saddam Hussein  by indicating, last week, that he will allow International Atomic Energy Agency inspectors into the North in coming months.

Still, if the summit is to be a success, analysts say, Koizumi will need concessions on a range of issues. Kim must clear the air on 20-year-old accusations that 11 Japanese were abducted by the North. He must also extend a moratorium on testing of the "No Dong" missiles, hundreds of which are currently aimed at Japan.

Analysts who say Koizumi is the only leader in Japan willing to propose internal reforms worry that the prime minister will harm himself politically if the summit fails. Most Japanese regard the North, much more than China, as a security threat, and welcome a decrease of tensions.

Perhaps as a result of these doubts, the Japanese have slightly scaled back expectations in recent days. "It is difficult to speak of normalization of relations with North Korea," says a foreign ministry source. "Koizumi will put everything on the table, [but] the prime minister's aim is simply to find out if there is the political will. Can Kim make a political decision to talk about all the issues?"

Japanese sources say there have been "more than 100 informal meetings" between Japanese and North Korean contacts over the past year, and a steady building of momentum leading up to the summit.

Japan, for its part, is taking great care that the summit does not overstep the good relations with the US that are a bedrock of Japan's foreign policy. Until now, the practical effect of the Bush approach in the region has been to put initiatives by allies Japan and South Korea on hold.

That is why Japan is approaching the summit with great care. "Japan wants to redirect a slow process, but not alienate its No. 1 ally, the US," says Ronald Montaperto, of the Asia-Pacific Center for Security Studies, a defense think-tank in Hawaii.

Former President Clinton supported the Sunshine Policy of reconciliation with the North that won South Korea's president a Nobel Prize. But since the early days of the Bush administration, diplomatic movement in North Asia has been in deep freeze. Bush pulled the plug on the Clinton "Perry Process," a US bid to engage the North that worked in tandem with South Korea's Sunshine Policy. Then Bush branded North Korea an "axis of evil," bringing diplomatic relations to a standstill.

"You can't have a Sunshine Policy and an 'axis of evil' policy at the same time," says one European scholar of Asia, in Beijing.

Now, the White House affirms that it will meet with North Korea for talks. Deputy Secretary of State Richard Armitage last week signaled that he might go to Pyongyang shortly after Koizumi. Though Bush administration hawks favor putting maximum immediate pressure on the North to halt its weapons exports, lesser hawks are willing to accept smaller victories.

"The US is not so concerned that Koizumi is out ahead [of the US]," a former US Bush administration official agrees. "We are more concerned that he get something for his efforts. The main question is: Has Kim really decided to open, or is this another of his gambits for face and money?"

"Mainly, what the US wants Kim to do is to start playing by the rules," says Mr. Montaperto, "The US and Japan have been working closely. What the US wants is a breaking of the cycle of Kim Jong Il relations," in which Kim makes promises, renegs on them, and hopes for better offers from neighbors. " I don't see how Kim loses anything by this," he says. "He pleases China, Russia, and South Korea. He needs Japan, and Japan funding. And he may pressure the US."

"In Japan, we are always making negative comments about North Korea," adds a foreign ministry official. "I've never heard any positive comments. But a certainty in the US that North Korea will one day fold is not enough. In the meantime we need to engage the North, to work toward dialogue, to pursue and explore. That is a fact of life in this part of the world."